The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Hydraulic accumulators generally include a piston that fits within a bore. Hydraulic fluid exerts pressure on one side of the piston. A spring or other biasing member acts on the piston in the opposite direction from the hydraulic force. The piston may include a piston ring or seal that seals between the piston and cylinder wall.
Referring now to FIG. 1, a cross-section is shown of a low pressure accumulator (LPA) 10 in accordance with the prior art. LPA 10 includes a cylinder or bore 12 that is formed in a housing 14. A piston 16 fits within bore 12. A spring 18 urges piston 16 towards the bottom of bore 12. A cover 20 closes one end of bore 12. Spring 18 compresses against an interior surface of cover 20. A seal 22 provides a seal between piston 16 and the wall of border 14.
During operation a fluid, such as brake fluid, enters an inlet port 24. The fluid displaces piston 16 upwards thereby compressing spring 18. The fluid can be released through an outlet port 26. Outlet port 26 may include a check valve 28. The volumetric capacity of LPA 10 is limited by the diameter of bore 12 and the stroke of piston 16. Increasing the volumetric capacity of LPA 12 therefore requires increasing the size of LPA 10.